1. Field of the Disclosure
The present disclosure relates generally to optical communication networks and, more particularly, to a system and method for asymmetrically compensating signal degradation induced by polarization dependent loss (PDL) in dual-polarization optical systems.
2. Description of the Related Art
Telecommunications systems, cable television systems and data communication networks use optical networks to rapidly convey large amounts of information between remote points. In an optical network, information is conveyed in the form of optical signals through optical fibers. Optical networks may also include various network elements, such as amplifiers, dispersion compensators, multiplexer/demultiplexer filters, wavelength selective switches, couplers, etc. configured to perform various operations within the network.
However, each of these network subsystems may also introduce polarization dependent effects on the optical signals traveling through the network. These effects may cause the different polarization components of the optical signals to experience different signal degradation due to polarization dependent loss (PDL). For example, PDL may cause an imbalance in the optical signal-to-noise ratio (OSNR) between polarization of the optical signal, such that one polarization component exhibits a degraded OSNR at a receiver compared to another polarization component. Furthermore, depending on the symbols transmitted, cross talk among polarization components due to PDL may result in intensity variations that are observed as nonlinear phase noise.